Recent years have witnessed increasing commercial progress of the virtual reality (VR) technology, which has eventually stepped out of labs. It is projected to form a substantial market by 2020. Users can now experience VR capabilities on their mobile devices using affordable VR devices such as a Google Cardboard. Immersive videos, also known as 360-degree videos or spherical videos, play an important role in a VR ecosystem. Such immersive videos provide users with panoramic views and create a unique viewing experience Immersive videos, such as 360-degree videos can be recorded by specially adapted cameras, such as omnidirectional cameras or camera array systems (e.g., Facebook Surround 360 Open Edition camera design and stitching code). They simultaneously record all 360 degrees of a scene that can be “wrapped” onto at least a portion of a 3D sphere, with the cameras at its center.